| 摘要 |
PURPOSE:To remove decay heat by detecting the pressure difference between the inlet and outlet of a recirculation flow passage valve, then by opening a spray supply valve to assure water in a steam separator when the detection signal attains a set differential pressure and by opening the recirculation flow passage valve when the water level in the separator attains a set water level. CONSTITUTION:The steam from a steam generator 1 after tripping of a nuclear reactor flows through a bypass valve 18 and a feed water heater 9 to a condenser 6 by bypassing a turbine 5. Since the flow rate of the feed water decreases, the differential pressure across the recirculation flow passage valve 14 increases from the negative toward the positive pressure. The differential pressure signal by a differential pressure detector 30 is inputted to a control circuit 31 and is compared with the set differential pressure. The spray supply valve 13 is opened when the differential pressure signal exceeds the set differential pressure. The feed water is then sprayed through a spray supply pipe 23 into the steam separator 4 by a nozzle 4 and is stored in the separator 4. The water level in the separator 3 is monitored by a water level gage 35. The valve 14 is opened by ANDing with the the open signal of the valve 13 when the monitored water level exceeds the set water level. The entire part of the system is thus maintained at the saturation temp. of water. |
